Drosophila melanogaster 
The Drosophila melanogaster genome is 165 Mb, with about 120 Mb of this being euchromatic. The genome is organized in 4 chromosome pairs and is estimated to contain 10–12,000 genes. Model organisms, such as Drosophila melanogaster, share many genes with humans whose sequences and functions have been conserved. In addition to myriad similarities in cellular structure and function, humans and Drosophila share pathways for intercellular signaling, developmental patterning, learning and behavior, as well as tumor formation and metastasis.
The genes involved in the development of Drosophila, with few exceptions, are the same as those involved in the development of higher organisms. Developmental biology studies the sequential activation and interaction of genes, in relation to developing morphology. Right now, Drosophila is the only organism for which one can begin with a list of genes active in the egg and follow the morphological changes and gene activations through to adulthood.
Drosophila studies have provided the widest knowledge base available for any single organism; accordingly, developmental biologists use the fly to ferret out the activity of genes with similar functions in higher organisms. Despite its small size, the fly is by no means a small developmental problem. If you know the genes involved in the development of the fly, you also know, to a reasonable approximation, the genes involved in the development of the worm, the fish, the mouse, and humans.
A major goal in insecticide development is to understand and elucidate the molecular mechanisms that govern cell signaling and cell—cell interactions in higher eukaryotes. Many proteins identified in Drosophila form major links in cellular communication/response systems. A complete list of proteins from Drosophila would therefore be invaluable in developing human therapeutic compounds and kinsecticidal agents. Not only will the proteins serve as models for human and invertebrate cellular signaling and response, such molecules will also serve as molecular keys in identifying therapeutically important human and other invertebrate orthologs.
Insecticides
About 10,000 species of the more than 1 million species of insects are crop-eating, and of these, approximately 700 species worldwide cause most of the insect damage to man's crops, in the field and in storage.
A detailed study of novel proteins from Drosophila and invertebrate orthologs thereof, will serve as targets for identifying new members of the known classes of insecticides as well as aiding in the identification of new classes of compounds.